Diet and nutrition and their effect on physical activity and exercise

Carbohydrates

simple and complex

simple carbohydrates

Found naturally in fruits, most processed foods and anything with added sugar.

Application (AO2): - carbohydrate meal in advance to an endurance based meal will provide the person with the glucose provided for the energy needed to compete - glucose + oxygen -> water + carbon dioxide + energy

Evaluation (A03): A lack of carbohydrates means the player cannot produce the energy needed to participate drastically impacting the performance potential.  Reduces the amount of energy produced reducing the performance and intensity and duration the player can perform.

complex carbohydrates

Found in nearly all plant based foods, it takes a long time to digest. Bread, pasta, rice and vegetables.

Application (AO2): - carbohydrate meal in advance to an endurance based meal will provide the person with the glucose provided for the energy needed to compete - glucose + oxygen -> water + carbon dioxide + energy

Evaluation (A03): A lack of carbohydrates means the player cannot produce the energy needed to participate drastically impacting the performance potential.  Reduces the amount of energy produced reducing the performance and intensity and duration the player can perform.

glycemic index

This ranks carbohydrates according to their effect on our blood glucose levels. This effects when they should be consumed in relation to activity”

high GI -allow slower release of energy - Should be consumed 3-4 hours prior to exercise

Low GI - allow quick release of energy (instant energy but short lasting) - Should be consumed 1-2 hours prior to exercise.

very low GI - allow very quick release of energy -  Can be consumed up until exercise along with water.

fats

unsaturated

saturated

cholesterol

saturated fats

-a type of fat containing a high proportion of fatty acids molecules without double bonds, considered to be less healthy in the diet than unsaturated fat.

Application (AO2): Fat is a concentrated source of energy  providing double the amount of energy than carbs. (9 kcal per gram) Used in aerobic/low intensity and long duration as it is a slow release energy source which needs more O2 to break it down. Used to transport fat soluble vitamins (A, D, E and K). HDL’s break down fatty deposits in the arteries.

Evaluation (AO3): High intake of saturated fats is associated with high blood cholesterol, excess weight (obesity). Bad for stamina/endurance, Limits range of movement/flexibility, Performer can overheat due to excess insulation, resulting diseases: Atherosclerosis, Coronary heart disease, diabetes, cancers and high blood pressure. LDL’s lead to fatty deposits developing in the arteries.

unsaturated fats

type of fat that contains less cholesterol and are therefore considered better for cardiovascular health 

Application (AO2): Fat is a concentrated source of energy  providing double the amount of energy than carbs. (9 kcal per gram) Used in aerobic/low intensity and long duration as it is a slow release energy source which needs more O2 to break it down. Used to transport fat soluble vitamins (A, D, E and K). HDL’s break down fatty deposits in the arteries.

Evaluation (AO3): High intake of saturated fats is associated with high blood cholesterol, excess weight (obesity). Bad for stamina/endurance, Limits range of movement/flexibility, Performer can overheat due to excess insulation, resulting diseases: Atherosclerosis, Coronary heart disease, diabetes, cancers and high blood pressure. LDL’s lead to fatty deposits developing in the arteries.

cholesterol

 A type of fat found in the blood. created by the liver and is carried by two types of lipoproteins. 

 Low density lipoproteins (LDL’s): needed in small amounts to support cell membrane and hormone development. The downside is that excess LDLs increase risk of heart disease (saturated and trans fats increase the amount of unwanted cholesterol in the blood. - very bad and leads to fatty deposits developing in the arteries 

High density lipoproteins (HDL’s):decrease risk of heart disease by removing unwanted LDL’s and transporting them back to the liver (regular exercise boosts HDL’s) - HDLs are great as they break down the fatty deposits

proteins

found in meat, fish, eggs, dairy, nuts, chickpeas, beans, seeds

a combination of many amino acids 

• non essential amino acids made in body 

• essential amino acids have to be ingested

(AO2): Minor source of energy, Used when body has exhausted glycogen and fat stores, Used for growth and repair of muscles, High intake for e.g. weightlifting, rugby and sprinting / injury recovery to repair damaged tissue

Evaluation (AO3): Insufficient protein leads to muscle atrophy due to proteins found in the muscles being taken for energy to keep the body alive. Leads to muscle loss and reduced strength. As insufficient protein means slower growth and repair for muscles which leads to slower recovery - 

muscle loss and reduced strength - protein is crucial for muscle growth and repair, without enough protein in the body, the body breaks down existing muscle tissue to meet the demand for proteins in other parts of the body, leading to muscle loss and reduced strength. For example they can be used in the immune system for the production of antibodies. 

slower recovery  - Protein is essential for repairing muscle damage after exercise. insufficient intake can delay recovery and increase the risk of injuries.

fibre

whole grain, high fibre cereals and bread

• dietary material containing substances such as cellulose, lignin and pectin that are resistant to the action of digestive enzymes. 

• helps the movement in the digestive system

Application (AO2): Slows energy break down / sustained energy release. Can help control blood glucose levels in diabetics. Can reduce blood cholesterol levels. Can act as a bulking agent to prevent constipation.

Evaluation (A03): Regular and consistent bowel movements would help an athlete train uninterrupted whilst also reducing any discomfort experienced from constipation and bloating.

aiding process of digestion - primarily important to allow natural ebb and flow of your body. aid natural flow of digestive system 

also makes you feel full - issue with modern diets - certain foods with high level of processing dont have much protein so don't make you feel as full

water

• humans = 60-70% water

• sun stroke - severe headaches

• happens sure to high external temperatures and due to dehydration

• Application (AO2): Transport of nutrients, hormones, and waste products.Provides the medium for reactions to take place. Acts as a lubricant for joints and eyes. Helps regulate body temperature.

  Evaluation (AO3): A lack of water can lead to dehydration. This can result in: 

  blood viscosity increasing, reducing blood flow - blood plasma reduced 

  reduced sweating leads to increase in body temperature 

  muscle fatigue and headaches

  reduction in the transport of nutrients and waste products 

  increased heart rate but reduced output of blood

  increased performance/ reaction time/ decision making/ endurance 

  can lead to heat stroke and death

  can be easily avoided by consuming water or electrolyte containing energy drinks

vitamin A

predominantly foudn iin fatty foods and animal products - milk dairy foods, vegetable oils, eggs, liver and oily fish

body stores these fat soluble vitamins in liver and fatty tissues for later use

(AO2):Essential to structure/function of the skin and mucous membranes.

Required for normal growth, vision and immune system.

Vitamin D

-Most is made by our body under the skin when it is exposed to sunlight. A small amount can come from oily fish and dairy produce. - fat soluble

has role in absorption of calcium, keeps bones and teeth healthy 

Vitamin E

predominantly foudn iin fatty foods and animal products - milk dairy foods, vegetable oils, eggs, liver and oily fish

body stores these fat soluble vitamins in liver and fatty tissues for later use

AO2): Essential in the control of blood sugar levels

Vitamin K

predominantly foudn iin fatty foods and animal products - milk dairy foods, vegetable oils, eggs, liver and oily fish

body stores these fat soluble vitamins in liver and fatty tissues for later use

AO2): Essential for the clotting of blood and bone structure.

Found in plant and animal sources and made by bacteria in the gut.

vitamin B1 thiamine

Whole grains, nuts and meat, especially pork.

Needed for the release of energy from carbs. Involved in normal function of the nervous system and the heart.

vitamin B2 - riboflavin

found in dairy products, liver, vegetables, eggs, cereals, fruit

works with other B group vitamins to help break down and release energy from food

keeps nervous system healthy

Vitamin B6

found in meat, eggs, fish, bread, vegetables, cereals

helps form haemoglobin

helps body to use and store energy from protein and carbohydrate in food

vitamin B12 - folate

found in red meat, dairy products and fish

makes red blood cells and keeps the nervous system healthy

releases energy from food

minerals

sodium

iron

calcium

sodium

• meat, eggs, fish, dairy products, cereals vegetables, fruit and nuts

Helps regulate body water content and electrolyte balance; involved in energy use and nerve function.

High levels are associated with high blood pressure.- increase risk of stroke or heart attack

Short term lack of salt leads to cramping through excess sweating

iron

• meat, eggs, fish, dairy products, cereals vegetables, fruit and nuts

• Formation of haemoglobin and O2 transport; energy metabolism; metabolism of foreign substances (removal).

A lack of iron leads to anaemia.

calcium

• meat, eggs, fish, dairy products, cereals vegetables, fruit and nuts

• Main mineral in bones and teeth. Necessary for nerve and muscle function.

dietary supplements

• enhance sporting performance

• glycogen loading

• creatine monohydrate

• sodium bicarbonate

• caffeine

glycogen loading

endurance= glycogen

6 days before competition, performer eats a diet high in protein for 3 days and exercises at relatively high intensity to burn off any existing carbohydrate stores - this is then followed by 3 days of a high diet in carbohydrates and some light training

theory is that totally depleting glycogen stores, they can then be increased unto 2 times the go amount and can prevent the performer from hitting a wall

form of dietary manipulation

positive effects of glycogen loading

• increased glycogen storage

• increased glycogen stores in the muscle

• delays fatigue

• increased endurance capacity

negative effects of glycogen loading

during the carbo-landing phase

• water retention, which results in bloating

• heavy legs

• affects digestion

• weight increase

during depletion phase

• irritability

• can alter the training programme through a lack of energy

creatine monohydrate

• supplement used to increase the amount of phosphocreatine stored in the muscles

• phosphocreatine is used to fuel the ATP-PC system which provides energy

• increasing amount of creatine allows energy system to last longer and also help improve recovery times

• explosive events = experience most benefits as they perform at a higher intensity for longer

positives of creatine monohydrate

• aims to provide ATP (energy)

• replenishes phosphocreatine stores

• allows ATP-PC system to last longer

• improves muscles mass

negatives of creatine monohydrate

• side effects - muscle cramps, water retention, bloating, diarrhoea, vomiting

• hinders aerobic performance

• mixed evidence show benefits

sodium bicarbonate

• antacid - increase buffering capacity of the blood so it can neutralise the negative effects of lactic acid and hydrogen ions that are produced in the muscle during high-intensity activity

• reduces acidity within the muscle cells, in order to delay fatigue and allows the performer to continue exercise at a very high intensity for longer

• however negatives outweigh positives as too often athletes choose not to due to the gastric disruption

positives of sodium bicarbonate

reduces acidity in muscle cells

high intensity for longer period of time

delays fatigue

increases buffering capacity of the blood

negatives of sodium carbonate

side effects - vomiting, diarrhoea, pain, cramping, bloating

caffeine

stimulant - increase mental alertness and reduce fatigue

also though to improve mobilisation of fatty acids in the body - thereby sparing muscle glycogen stores

used by endurance performers who use predominantly aerobic systems since fats are preffered fuel for low intensity, long durance exercise

found in coffee, tea, cola, chocolate, energy bars with caffeine and caffeinated gels

positive effects of caffeine

• stimulant/increased mental alertness

• reduces effects of fatigue

• allow fats to be sued as an energy source/ delays use of glycogen stores

• improves decision making/ improves reaction time

• may benefit aerobic performance/ endurance athletes

negative effects of caffeine

loss of fine control

against rules of most sports in large quantities

side effects - dehydration, insomnia, muscle cramps, stomach cramps, vomiting, irregular heartbeat, diarrhoea